I worked for a shady evil company, and when they illegally fired me, I never ended up returning a laptop - thinkpad running windoze.
Let’s say I wanted to put Win 8 or similar on it so I can play some video games. What would potentially be barriers to doing this? Said evil company is hopefully going out of business soon, and is a clusterfuck anyway, so they might not end up asking for it back.
Still, it’s probably worth going with either 7 or 10.
Also, if it’s registered with InTune (or whatever it’s called nowadays), it may be under company control even after a completely clean install. You can easily check though.